Interesting graph plotting followers vs Tweet volume. Looks like there are three clear phases: 1) use it to tweet a "what is this for" message and then nothing, 2) put a few updates a day on (from a blog maybe) and 3) a fairly steady ramp up after 800 followers. It looks tantalisingly like it steadies off at about 10 per day, but that´s not scientific in the slightest. PS in the comments, it´s clear to see that the old waz business model is still working (summary: send a market share table to people that´s slightly guesswork and have them respond with anger giving the correct numbers).